SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03a48a6151fb7ede7322fcfa7eea9957dd557a06c506da5e5e1a4d45d3bfe934' 
  AND token = 'Gs9u0KvstEjXAL4lg0czoPkixczS8/vJrkQaIDzoU/M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}